A comparison of language characteristics of mentally retarded adults with fragile X syndrome and those with nonspecific mental retardation and autism.
Fragile X and general ID adults talk alike—only echoing speech points to autism.
01Research in Context
What this study did
Paul et al. (1987) compared how three groups of adults living in the same residential center talk.
The groups were fragile X syndrome, nonspecific mental retardation, and autism plus retardation.
Staff gave standard language tests and counted echolalia during short conversations.
What they found
Fragile X and nonspecific MR adults scored the same on every language measure.
Only the autistic group stood out—they echoed words and phrases far more often.
No other language skill separated the three diagnoses.
How this fits with other research
Howlin et al. (2006) looked at younger FXS adults and found that those who also have autism understand far fewer words, even when IQ is matched.
The 1987 adults showed no such gap—age and test type may explain the shift.
Yuhas et al. (2011) measured brain-based sensorimotor gating and saw clear splits between idiopathic autism and FXS-autism, yet the 1987 paper saw none on plain language tests.
The studies do not clash—they simply checked different body systems: one language, one reflex circuits.
Why it matters
When you assess an adult with ID and fragile X, expect ordinary expressive language; do not assume delay.
Use echolalia as a quick red flag for possible autism in this population.
If the client echoes often, probe social and receptive skills more deeply—later work shows hidden gaps can live there.
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02At a glance
03Original abstract
Fragile X syndrome is a recently identified form of mental retardation that is associated with a chromosomal abnormality and inherited in an X-linked manner. Previous studies have suggested that distinctive speech and language characteristics are associated with the syndrome. Twelve adult male residents of an institution for the retarded (aged 23 to 51 years) were compared on a series of speech and language measures to 12 adult males with nonspecific forms of MR who were residents of the same institution and were matched on age and IQ. A second contrast group consisted of similarly matched autistic men. Results revealed that there were no significant differences among the groups' performance, with the exception of increased rates of echolalia in the autistic group. A nonsignificant trend toward poorer performance on expressive measures on the part of the fragile X group was noted. The implications of these findings for further research on the syndrome are discussed.
Journal of autism and developmental disorders, 1987 · doi:10.1007/BF01486963